We begin our numerical analysis by considering a composite material made of \(SiO_2\)  as host medium with relative permittivity \(\epsilon _h=2.1\)  [1]} and dielectric spherical inclusions of radius \(20 \,\rm nm\) , bulk relative permittivity \(\epsilon _i=169\)  [2]}, [3]} and volume filling fraction \(f\) . The effective optical constants of the composite material are calculated by EMG theory (Sec. REF ). Since the inclusions have a large refractive index so that the incident field can generate displacement currents inside the inclusions and produces tiny magnetic dipoles. The collective effect of these spherical magnetic dipoles generates a remarkable magnetic response in the composite metamaterials.
The effective optical response of the composite metamaterials is measured in terms of effective permittivity and effective permeability by using the Eqs. (REF -REF ) that have external degrees of freedom, like volume filling fraction, permittivities and size of inclusions. One can perform fine tuning of these parameters to tailor the resonance at a chosen wavelength for operation.
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